FILE -- June 15, 2014: Iraqis attend Mass at the Chaldean Church of the Virgin Mary of the Harvest, in al-Qoush, set in the seventh century Saint Hormoz monastery built into a hill overlooking Alqosh, a village of some 6,000 inhabitants about 50 kilometers (31 miles) north of Mosul, northern Iraq. ( AP)Three years ago ISIS began attacking Iraq's Christians and Yizidis in an onslaught of rape, murder and ruin that was properly designated as "genocide" on March 17, 2016 by the State Department.

Now, as their hometowns in Iraq's northern Nineveh Province become liberated in an ongoing coalition offensive, a few brave Christian and Yizidi genocide survivors are straggling back to the rubble that was once their homes and businesses.

The next six months will be the moment of truth for them.

This period will determine whether these ancient communities -- some of whom still speak Aramaic, the language of Jesus of Nazareth and trace their faith to Thomas the Apostle -- will be able to leave the squalid refugee camps and displacement shelters to return home. It will determine whether they can rebuild their shattered lives in the lands their families have lived in for millennia.

The imminent defeat of ISIS' control over Nineveh is necessary. But these genocide survivors need more help and protection if they are to survive.

While the Obama State Department acknowledged the genocide, it took little diplomatic action to help its survivors.

As the Chaldean Catholic Archdiocese of Erbil told Congress, on September 22, it has received no U.N. or State Department USAID-administered humanitarian aid for 70,000 genocide survivors, since 2014. This encompasses the largest community of Iraqi Christian refugees, as well as some Yizidis under its care.

In the State Department's recently-released human rights annual reports for Iraq -- drafted under the Obama administration -- there was no mention whatsoever of ISIS' genocide in Iraq, though genocide is the world's worst human rights atrocity, one about which, after the Jewish Holocaust, we solemnly vowed never again to be silent.

There is a new danger that Christian areas will be omitted from U.N. reconstruction plans and an ISIS' genocide investigation in Iraq to be initiated by the U.N. Security Council. Nothing can justify such oversights.

Before the 2003 U.S. invasion, Iraq had 1.4 million Christians. After being killed or driven out, they now they number about 250,000. Incredibly, despite everything that's happened, Iraq's Christian community remains the Middle East's fourth largest indigenous Christian community. We should be doing more to preserve it. We should be helping all these beleaguered minorities.

Christian sources tell me that two Christian families have returned to Mosul, an overwhelmingly Sunni Muslim city of 2 million, whose western part remains a war zone.

Several hundred more Christian families have gone home to a handful of majority-Christian villages close to Kurdistan, including Teleskof, where U.S. Navy SEAL Charlie Keating IV lost his life last May, fighting to liberate it.

Nineveh's largest Christian city, Qaraqosh, which is not within the protection zone of Kurdish Peshmerga forces, sits as a ghost town, the walls of its homes and churches still reek of the oil and fires from when the jihadis laid waste to it.

Bartella and other nearby once-Christian towns are now controlled by Iranian-backed militias who man check-points there and populated mainly by Shiites flush with money, likely provided by Iran.

Singar, the Yizidi center in western Nineveh, was liberated over a year ago, but only a few families have resettled there. It lies in ruins and over a dozen mass graves, filled with its former residents, remain untouched. This month, skirmishes broke out between Yizidi and Kurdish militias formed to protect it.

President Trump, at the National Prayer Breakfast this month, and Vice President Pence, in a recent tweet, have acknowledged the genocide suffered by these minority faith communities. They now should act.

U.N. Ambassador Nikki Haley should be instructed to ensure that the U.N. fairly assists each of these vulnerable minorities in its aid and reconstruction programs and in genocide investigations.

Amb. Haley has already been a bold voice for the reform of glaring human rights imbalances at the U.N. She must address this one as well.

At a March 22 State Department summit being convened with 68 state members of the anti-ISIS coalition, Secretary of State Rex Tillerson should lead to ensure continuing protection, help and investment for these genocide-targeted minorities.

After all these centuries, without more Western help, these minority communities will not be able to survive a rapidly radicalizing Middle East.

Nina Shea has worked as a lawyer specifically focusing on religious freedom in American foreign policy, for thirty years. Joining the Hudson Institute as a Senior Fellow in 2006, she has led the Center for Religious Freedom, which she founded in 1986, in its effort to defend religious freedom internationally. She currently is a leader of a campaign for Christians threatened with genocide by ISIS.